US 4,325,764 A · Drum and method of shaping a radial tire

Abstract

A radial tire carcass fabricated by a first stage process has bead portions which are placed over a pair of spaced-apart coaxial bead seats. The bead seats may be segmented radially expandable rings which are expanded by fluid pressure into engagement with the bead portions. The tire carcass is initially positioned on the drum with the bead seats at a spaced-apart distance so that upon expansion of the segments of the bead seats at a low pressure and axial movement apart of the bead seats the ply of the tire carcass is stretched and the bead portions moved into register on the bead seats. The fluid pressure expanding the segments of the bead seats is then increased to secure the bead portions on the bead seats at predetermined positions with a predetermined diameter. Annular sealing members may be mounted on the segments of the bead seats at the tire-supporting surfaces of the segments for compression upon application of high pressure. The sealing members may also have flaps for bridging the space between the bead portions of the tire and mounting rings for the segments of the bead seats so that the tire may be inflated after registration of the bead portions and while the bead seats are moved axially together for the application of the tread and belt ply.

Claims11

Dependent claims

A radial tire building machine shaping drum rotatable about an axis comprising a segmented radially expandable inboard ring, a segmented radially expandable outboard ring spaced axially from said inboard ring, said outboard ring and said inboard ring each having a plurality of separate radially movable drum segments slidably mounted at circumferentially spaced positions on corresponding mounting rings, means for radially moving said drum segments, each of said drum segments having a generally cylindrical radially outer supporting surface with a bead seat for engagement of said surface with one of the bead portions of the tire before seating on said bead seat upon radially outward movement of each of said segments, means for axially moving said outboard ring and said inboard ring in opposite directions to seat said bead portions on said bead seat on each of said drum segments and to spread and contract the bead portions of the tire, and means for inflating the tire mounted on said outboard and inboard rings.

A method of building a radial tire comprising:

A. fabricating at a first location a first stage tire carcass including at least one radial ply in generally cylindrical form extending between a pair of annular inextensible beads located at spaced-apart bead portions;
B. placing said carcass about tire shaping means at a second location with said bead portions being supported on a pair of supporting surfaces having bead seats;
C. positioning said bead seats coaxially and at a spaced-apart distance less by a predetermined amount than the distance between said spaced-apart bead portions of said first stage tire carcass;
D. expanding said supporting surfaces radially by fluid pressure to engage circumferentially said bead portions;
E. moving said supporting surfaces axially apart by a distance sufficient to register said bead portions on said bead seats and exert an axial tension on said radial ply;
F. expanding said bead seats radially to a predetermined diameter by increasing said fluid pressure to secure said bead portions on said bead seats in the registered positions;
G. moving said bead seats and said bead portions together while radially expanding said radial ply therebetween for the application of a belt ply and tread;
and
H. retracting said bead seats and removing said fabricated and shaped tire from said tire shaping means.

6 more elements

Dependencies are inferred from the claim text.

Drum and method of shaping a radial tire

Life of this patent

Drum and method of shaping a radial tire

Life of this patent

Abstract

Claims11